<!DOCTYPE html>
<head>
    <meta charset="UTF-8">
    <title>边框颜色</title>
    <style type="text/css">
        div{
            /* background-color: red; */
            width:500px;
            height:500px;
            /* border-style:dashed;
            border-width:20px;
            border-color:#0000FF #008000 #00FFFF #DEB887; */
            /* border-top-color:#0000FF;
            border-right-color:#008000;
            border-bottom-color:#00FFFF;
            border-left-color:#DEB887; */
            /* border:20px dashed yellow; */
            /* border-width border-style border-color
            border-top/right/bottom/left-width/style/color; */
            border:2px solid;
            border-radius: 20px;
        }
    </style>
</head>
<body>
    <div></div>
</body>
</html>